<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<!-- html  生成 柱状图 -->
</head>
<body>
<canvas id="a_canvas" width="1000" height="700"></canvas>
<script>
    (function (){
 
        window.addEventListener("load", function(){
 
          var data = [1000,1300,2000,3000,2000,2000,1000,1500,2000,5000,1000,1000];
          var xinforma = ['1月','2月','3月','4月','5月','6月','7月','8月','9月','10月','11月','12月'];
 
          // 获取上下文
          var a_canvas = document.getElementById('a_canvas');
          var context = a_canvas.getContext("2d");
 
 
          // 绘制背景
          var gradient = context.createLinearGradient(0,0,0,300);
 
 
         // gradient.addColorStop(0,"#e0e0e0");
          //gradient.addColorStop(1,"#ffffff");
 
 
          context.fillStyle = gradient;
 
          context.fillRect(0,0,a_canvas.width,a_canvas.height);
 
          var realheight = a_canvas.height-15;
          var realwidth = a_canvas.width-40;
          // 描绘边框
          var grid_cols = data.length + 1;
          var grid_rows = 4;
          var cell_height = realheight / grid_rows;
          var cell_width = realwidth / grid_cols;
          context.lineWidth = 1;
          context.strokeStyle = "#a0a0a0";
 
          // 结束边框描绘
          context.beginPath();
          // 准备画横线
          /*for(var row = 1; row <= grid_rows; row++){
            var y = row * cell_height;
            context.moveTo(0,y);
            context.lineTo(a_canvas.width, y);
          }*/
          
            //划横线
            context.moveTo(0,realheight);
            context.lineTo(realwidth,realheight);
                
             
            //画竖线
          context.moveTo(0,20);
           context.lineTo(0,realheight);
          context.lineWidth = 1;
          context.strokeStyle = "black";
          context.stroke();
              
 
          var max_v =0;
          
          for(var i = 0; i<data.length; i++){
            if (data[i] > max_v) { max_v =data[i]};
          }
          max_v = max_v * 1.1;
          // 将数据换算为坐标
          var points = [];
          for( var i=0; i < data.length; i++){
            var v= data[i];
            var px = cell_width *　(i +1);
            var py = realheight - realheight*(v / max_v);
            //alert(py);
            points.push({"x":px,"y":py});
          }
 
          //绘制坐标图形
          for(var i in points){
            var p = points[i];
            context.beginPath();
            context.fillStyle="green";
            context.fillRect(p.x,p.y,15,realheight-p.y);
             
            context.fill();
          }
          //添加文字
          for(var i in points)
          {  var p = points[i];
            context.beginPath();
            context.fillStyle="black";
            context.fillText(data[i], p.x + 1, p.y - 15);
             context.fillText(xinforma[i],p.x + 1,realheight+12);
             context.fillText('月份',realwidth,realheight+12);
             context.fillText('资金量',0,10);
              }
        },false);
      })();
       
</script>
</body>
</html>